Introduction Tumor lysis syndrome (TLS) is an oncologic emergency characterized by several metabolic derangements, such as hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. TLS is typically observed in hematologic malignancies, especially after starting the first administration of antineoplastic therapies. TLS in a solid malignancy is very unusual, and exceedingly rare when occurring spontaneously, in the absence of chemotherapy. Case Presentation We report a case of a 76-year-old man with lung adenocarcinoma, which started as a cancer with indolent behavior and small tumor burden but relapsed in 5 months with rapidly proliferating metastatic disease. Spontaneous TLS was the presenting clinical manifestation of the tumor relapse, and it led to the patient's death. Conclusion To our knowledge, this is the first case of spontaneous TLS in a relapsed adenocarcinoma of the lung reported in the medical literature. The development of the metabolic derangements of TLS should prompt the consideration of tumor relapse during the follow-up of patients with solid malignancies.

中文翻译：

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肺腺癌复发表现为自发性肿瘤溶解综合征。

简介 肿瘤溶解综合征 (TLS) 是一种肿瘤急症，其特征是多种代谢紊乱，如高尿酸血症、高钾血症、高磷血症和低钙血症。TLS 通常在血液系统恶性肿瘤中观察到，尤其是在开始第一次抗肿瘤治疗后。实体恶性肿瘤中的 TLS 非常罕见，并且在没有化疗的情况下自发发生时极其罕见。病例介绍 我们报告一例患有肺腺癌的 76 岁男性，该病一开始是一种行为惰性、肿瘤负荷较小的癌症，但在 5 个月内复发，并出现快速增殖的转移性疾病。自发性TLS是肿瘤复发的临床表现，并导致患者死亡。结论 据我们所知，这是医学文献中报道的首例复发性肺腺癌自发性 TLS 病例。TLS 代谢紊乱的发展应促使在实体恶性肿瘤患者的随访过程中考虑肿瘤复发。